I/O instructions

I/O instructions
Name	Description	Code	Operation	operands	operand size
in	Read from a port	in dest, port	transfer value from input port to dest	al, const ax, const eax,const al, dx ax, dx eax,dx	byte,byte word,byte dword,byte
out	Write to a port	out port, source	transfer value to output port from source	const, al const, ax const, eax dx, al dx, ax dx, eax	byte,byte byte,word byte,dword

Name

Description

Code

Operation

operands

operand size

Read from a port

in dest, port

transfer value from input port to dest

al, const
ax, const
eax,const

al, dx
ax, dx
eax,dx

byte,byte
word,byte
dword,byte

out

Write to a port

out port, source

transfer value to output port from source

const, al
const, ax
const, eax

dx, al
dx, ax
dx, eax

byte,byte
byte,word
byte,dword